1. Technical Field
Various embodiments generally relate to a semiconductor technology, and more particularly, to a three-dimensional nonvolatile memory device.
2. Related Art
Because two-dimensional nonvolatile memory devices have reached a limit in terms of memory cells formed in a single layer on a substrate, a three-dimensional nonvolatile memory device in which memory cells are arranged three-dimensionally on a substrate so as to enhance the degree of integration has been proposed.
In the three-dimensional nonvolatile memory device, a desired memory cell is operated by applying bias to corresponding word lines which are stacked on the substrate, forming a multi-layer structure. For this to occur, pad portions are formed on the respective word lines in a slimming region. Through contact plugs, the pad portions of the word lines are electrically coupled to wiring lines lying over the pad portions.